Analog Devices Inc./Maxim Integrated MAX6865UK46D3S+T

Overview

The MAX6865UK46D3S+T from Maxim Integrated is a nanopower microprocessor supervisory circuit in a 5-pin SOT23 package, featuring ultra-low 170nA typical supply current, factory-trimmed 4.625V reset threshold (±2.5%), 150ms minimum reset timeout, manual reset input (MR), and watchdog timer with 3.3s typical timeout. It asserts an active-high push-pull RESET during VCC brownout, MR assertion, or watchdog expiration - used in battery-powered medical monitors and portable instrumentation.

For engineers reviewing the MAX6865UK46D3S+T datasheet, MAX6865UK46D3S+T pinout, MAX6865UK46D3S+T application, or MAX6865UK46D3S+T equivalent, this page delivers verified electrical parameters, functional pin mapping, real-world use cases, and validated alternative options for low-power µP reset and watchdog supervision.

Technical Context

The MAX6865UK46D3S+T integrates voltage monitoring, manual reset control, and a watchdog timer in a single BiCMOS IC. Its reset logic triggers on VCC falling below 4.625V, MR low, or WDI inactivity exceeding 3.3s (typ), with guaranteed RESET validity down to VCC = 1.1V and immunity to ≤40µs VCC transients at 100mV overdrive.

It uses an internal 10kΩ MR pullup and supports CMOS-level WDI edge detection (min pulse width 150ns). The active-high push-pull RESET output sources ≥500µA at VCC ≥ 2.38V and remains asserted for ≥150ms after fault clearance.

Key Specifications

Pinout & Package

Package: 5-pin SOT23-5, lead-free, -40°C to +85°C operating range.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar microprocessor supervisory applications.

Compared with MAX6864UK46D3S+T and TPS3836K33DBVR, the MAX6865UK46D3S+T uniquely combines 4.625V precision supervision, 150ms reset hold, 3.3s watchdog, and nanopower operation - making it irreplaceable in long-life 5V battery-powered medical devices.

Availability

MAX6865UK46D3S+T is available at Aetrix Electronics and suitable for portable medical monitoring, battery-powered industrial sensors, low-power wearable electronics, and embedded test equipment requiring stable component supply across extended production lifecycles.

Supply support for MAX6865UK46D3S+T includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Maxim Integrated (now part of Analog Devices) designs precision analog and mixed-signal ICs for power management, sensing, and interface applications in industrial, medical, and communications markets.

The MAX6854–MAX6869 family delivers nanopower µP supervision with integrated watchdog and manual reset - engineered specifically for battery-constrained portable and medical electronics demanding multi-year operation and fail-safe reliability.

FAQ

What is the exact reset threshold voltage of the MAX6865UK46D3S+T?

The MAX6865UK46D3S+T has a factory-trimmed reset threshold voltage of 4.625V, with a tolerance of ±2.5% over the -40°C to +85°C temperature range. This value is confirmed in Table 2 (Threshold Suffix Guide) of the datasheet, where suffix "46" corresponds to 4.625V nominal. The MAX6865UK46D3S+T maintains this accuracy without external calibration components.

Does the MAX6865UK46D3S+T include a watchdog timer, and what is its timeout period?

Yes, the MAX6865UK46D3S+T includes a watchdog timer with a typical timeout period of 3.3s, indicated by the "S" suffix in the part number. This is specified in Table 3 (Watchdog Timeout) and applies across the full operating temperature range. The MAX6865UK46D3S+T clears the watchdog timer on any WDI edge (rising or falling) and asserts RESET if no transition occurs within the timeout window.

What type of RESET output does the MAX6865UK46D3S+T provide, and how is it configured?

The MAX6865UK46D3S+T provides an active-high push-pull RESET output, as confirmed by its pin description (Pin 1 = RESET, active-high) and Selector Guide entry. This configuration eliminates the need for an external pullup resistor and directly interfaces with µP reset inputs expecting a high-level assertion. The MAX6865UK46D3S+T sources ≥500µA at VCC ≥ 2.38V, ensuring robust drive strength.

What is the minimum reset timeout period for the MAX6865UK46D3S+T, and how is it selected?

The MAX6865UK46D3S+T has a fixed minimum reset timeout period of 150ms, denoted by the "D3" suffix in the part number per Table 4 (Reset Timeout Periods). Unlike MAX6861–MAX6863 variants, the MAX6865UK46D3S+T does not feature a CT pin for runtime selection - its timeout is factory-set and immutable. This ensures predictable reset hold time in safety-critical applications.

How does the MAX6865UK46D3S+T handle supply voltage transients, and what is its immunity level?

The MAX6865UK46D3S+T is immune to short VCC transients up to 40µs duration when the overdrive is 100mV, as shown in the "Maximum VCC Transient Duration vs. Reset Threshold Overdrive" graph (Figure MAX684 toc05). This immunity prevents spurious resets in electrically noisy environments such as motor-driven industrial sensors or portable devices with switching regulators. The MAX6865UK46D3S+T guarantees this behavior across its full -40°C to +85°C operating range.